More improvements to knowledge base

1 files changed, 1 insertions, 1 deletions

diff --git a/source/know/concept/matsubara-greens-function/index.md b/source/know/concept/matsubara-greens-function/index.md
index fd46abf..5e753db 100644
--- a/source/know/concept/matsubara-greens-function/index.md
+++ b/source/know/concept/matsubara-greens-function/index.md
@@ -11,7 +11,7 @@ layout: "concept"
 The **Matsubara Green's function** is an
 [imaginary-time](/know/concept/imaginary-time/) version
 of the real-time [Green's functions](/know/concept/greens-functions/).
-We define as follows in the imaginary-time
+We define it as follows in the imaginary-time
 [Heisenberg picture](/know/concept/heisenberg-picture/):
 
 $$\begin{aligned}